DE102010041920A1 - Method for representing concentration of contrast agent in predetermined volume portion of female breast, involves subtracting two dimensional low-energy image of female breast from two dimensional high-energy image - Google Patents

Abstract

The method involves controlling the concentration of contrast agent and creating the two-dimensional low-energy image (1) and high-energy image of predetermined volume portion of female breast, by using low and high radiation energy beams respectively. A high-energy tomosynthesis process of volume portion is performed with high total radiation energy beam higher than low energy beam. Two dimensional low-energy image is subtracted from two dimensional high-energy image to visualize the concentration of contrast agent. Independent claims are included for the following: (1) tomosynthesis device; (2) computer program product for representing concentration of contrast agent in predetermined volume portion of female breast; and (3) electronically readable data carrier storing electronically readable control information for representing concentration of contrast agent in predetermined volume portion of female breast.

Description

The present invention relates to a method for displaying a concentration of a contrast agent or the course of the concentration of the contrast agent in a predetermined volume section by means of a tomosynthesis, as well as a correspondingly designed tomosynthesis apparatus.

To distinguish between malignant and benign lesions or tumors, it is known to administer a contrast agent for the volume section to be examined, and to make a corresponding assessment of the lesion or of the tumor on the basis of the dynamics of the contrast agent concentration. Especially in malignant tumors due to the neovascularization an accumulation of the contrast agent in the tumor, which is usually very fast (about within 1 min) takes place. Thus, to measure this increase in contrast agent concentration, fast imaging is required. A tomosynthesis scan typically lasts up to 25 s, during which time the contrast agent concentration within the volume segment to be displayed in the enrichment phase changes greatly, which leads to reconstruction problems in the tomosynthesis, since inconsistent data from the tomosynthesis scans occur during the tomosynthesis scan different angles (due to the time-varying contrast agent concentration) are detected.

The present invention therefore has as its object to better represent or measure the contrast agent concentration and / or the course of the contrast agent concentration, as is possible in the prior art.

According to the invention this object is achieved by a method for displaying a concentration of a contrast agent in a predetermined volume portion according to claim 1 or claim 11, by a tomosynthesis apparatus according to claim 18 or 20, by a computer program product according to claim 22 or by an electronically readable data carrier according to claim 23 , The dependent claims define preferred and advantageous embodiments of the present invention.

• • Erstellen eines zweidimensionalen Niedrigenergiebildes (Mammographie) des vorbestimmten Volumenabschnitts mit einer niedrigen Röntgen-Strahlenenergie bzw. Röntgen-Strahlendosis (z. B. im Bereich von 20 bis 35 kVp). Dabei wird das Niedrigenergiebild insbesondere in einer Standard-Screening-Projektion (CC oder MLO) oder seltener als eine Diagnostikaufnahme (Spotkompression, Vergrößerungsmammografie) erstellt. Bei der Ausrichtung CC (”Cranial Caudal” (vom Kopf zum Fuß)) werden die Röntgenstrahlen derart erzeugt, d. h. die Röntgenröhre wird derart ausgerichtet, dass die Röntgenstrahlen lotrecht bzw. vertikal verlaufen. Demgegenüber verlaufen die Röntgenstrahlen bei der Ausrichtung MLO (”Medio Lateral Oblique”) mit einem bestimmten Winkel zur lotrechten Ausrichtung.
• • Erstellen eines oder mehrerer zweidimensionaler Hochenergiebilder (Mammographie) des vorbestimmten Volumenabschnitts mit einer hohen Röntgen-Strahlenenergie (z. B. im Bereich von 40 bis 50 kVp), welche wesentlich höher als die niedrige Röntgen-Strahlenenergie des Niedrigenergiebilds ist. Dabei wird das oder werden die Hochenergiebilder insbesondere nach dem Niedrigenergiebild erstellt, wobei die Ausrichtung zur Erstellung des bzw. der Hochenergiebilder insbesondere dieselbe wie die Ausrichtung bei der Erstellung des Niedrigenergiebilds ist.
• • Durchführen einer Hochenergie-Tomosynthese des vorbestimmten Volumenabschnitts.
• • Automatisches Subtrahieren des zweidimensionalen Niedrigenergiebildes von dem mindestens einen zweidimensionalen Hochenergiebild. Wenn es sich nur um ein Hochenergiebild handelt, wird das Niedrigenergiebild von diesem Hochenergiebild gewichtet subtrahiert. Bei mehreren Hochenergiebildern wird das Niedrigenergiebild von jedem dieser Hochenergiebilder gewichtet subtrahiert. Durch diese Subtraktion wird ein Ergebnis bzw. Ergebnisbild erzeugt, auf welchem die Konzentration des Kontrastmittels sichtbar ist. Dieses Subtrahieren wird auch als nicht temporäre Dual-Energie-Subtraktion (”Non Temporal Dual Enery Subtraction” oder ”Dual Enery Subtraction”) bezeichnet.
• • Insbesondere werden Bilddaten einer früheren Niedrigenergie-Tomosynthese, welche vor der Verabreichung des Kontrastmittels durchgeführt wurde, von Bilddaten der Hochenergie-Tomosynthese subtrahiert, was auch als temporäre (zeitliche). Dual-Energie-Subtraktion (”Temporal Dual Energy Subtraction”) bekannt ist.

In the context of the present invention, a method is provided for displaying a concentration of a contrast agent in a predetermined volume section of an examination subject by means of a tomosynthesis apparatus. In this case, the method comprises the following steps after a mostly intravenous administration of the contrast agent:

• • Create a low energy, two-dimensional image (mammography) of the predetermined volume fraction with a low X-ray radiation dose (eg in the range of 20 to 35 kVp). The low-energy image is created in particular in a standard screening projection (CC or MLO) or, more rarely, as a diagnostic image (spot compression, magnification mammography). In CC ("cranial caudal"), X-rays are generated in this way, ie, the X-ray tube is oriented so that the X-rays are perpendicular. In contrast, the x-rays in the alignment MLO ("Medio Lateral Oblique") with a certain angle to the vertical orientation.
• • Create one or more two-dimensional high energy (mammography) images of the predetermined volume segment with a high x-ray energy (e.g., in the range of 40 to 50 kVp) that is substantially higher than the low x-ray energy of the low energy image. In particular, the high-energy image (s) is / are created according to the low-energy image, wherein the orientation for creating the high-energy image (s) is in particular the same as the alignment when the low-energy image is created.
• • Performing a high-energy tomosynthesis of the predetermined volume section.
• • Automatically subtracting the two-dimensional low energy image from the at least one two-dimensional high energy image. If it is just a high energy image, the low energy image from that high energy image is subtracted weighted. For multiple high energy images, the low energy image from each of these high energy images is subtracted weighted. This subtraction produces a result or result image on which the concentration of the contrast agent is visible. This subtraction is also referred to as non-temporary dual energy subtraction ("Non Temporal Dual Enery Subtraction" or "Dual Enery Subtraction").
• In particular, image data from a previous low-energy tomosynthesis performed prior to administration of the contrast agent is subtracted from image data of high-energy tomosynthesis, also as a temporal. Dual Energy Subtraction ("Temporal Dual Energy Subtraction") is known.

While the spectrum (more specifically the centroid of the spectrum) of the X-rays for generating the high energy images is well above the K-edge of the contrast agent, the spectrum (more specifically the centroid of the spectrum) of the X-rays for generating the low energy image is well below this K-edge. When using an iodine contrast agent is thus with a tube voltage of well above 33 kVp (the iodine absorption edge or K-edge is 33 kV) to create a high energy image and with a tube voltage of well below 33 kVp worked to create a low energy image. (When using gadolinium as a contrast agent, it would be necessary, for example, to work with a much harder radiation than the iodine in order to produce the high-energy image.) As a result, the x-ray photons generate enough energy to create an electron of a contrast agent atom when creating the high-energy image remove the K-shell, so that the contrast medium absorbs at least a portion of the X-ray radiation. In contrast, the X-ray photons in the creation of the low energy image (usually) not enough energy to remove an electron of a contrast agent from the K-shell, so that the X-rays from the contrast agent is not absorbed.

Similarly, the individual projections of high-energy tomosynthesis are made with tube radiation whose spectrum is well above the K-edge of the contrast agent, while the individual projections of low-energy tomosynthesis are made with an X-ray whose spectrum is well below this K-edge lies. Since the x-ray energy or dose is usually determined by the product of the high voltage (with which the x-ray tube operates), the tube current and the recording time (switching time), the tube voltage (and thus the energy of the individual x-ray photons) can be used to take a single image and be the same for recording a projection of a tomosynthesis, but still be the X-ray dose to produce the projection significantly lower than the X-ray dose to create the single image.

• • Die Projektionen des Niedrigenergie-Tomosynthese-Scans werden mit den entsprechenden Projektionen des Hochenergie-Tomosynthese-Scans registriert (eventuell mit Einsatz einer Winkelinterpolation), und dann eine Subtraktion der jeweiligen Projektion des Niedrigenergie-Tomosynthese-Scans von der jeweiligen Projektion des Hochenergie-Tomosynthese-Scans durchgeführt, wobei anschließend eine Rekonstruktion von Schichtbildern vorgenommen werden kann.
• • Aus dem Niedrigenergie-Tomosynthese-Scan wird eine bestimmte Schicht innerhalb des vorbestimmten Volumenabschnitts rekonstruiert, während aus dem Hochenergie-Tomosynthese-Scan ein dreidimensionales Modell des vorbestimmten Volumenabschnitts erstellt wird, welches pro Voxel auch eine Information über den Kontrastmittelgehalt pro Zeitpunkt enthält. Aus diesem dreidimensionalen Modell werden zu jeweils unterschiedlichen Zeitpunkten Schichtbilder der bestimmten Schicht rekonstruiert, welche dann jeweils eine Information über den dem Zeitpunkt entsprechenden Kontrastmittelgehalt enthalten. Anders ausgedrückt wird erst eine Rekonstruktion und dann eine Subtraktion der (insbesondere registrierten und bewegungskorrigierten) Schichten durchgeführt.

In order to subtract the image data of the low energy tomosynthesis scan from the image data of the high energy tomosynthesis scan, there are several possibilities:

• • The low energy tomosynthesis scan projections are registered with the corresponding projections of the high energy tomosynthesis scan (possibly using angle interpolation), and then a subtraction of the respective low energy tomosynthesis scan projection from the respective high energy tomosynthesis projection Scans performed, with subsequent reconstruction of layer images can be made.
• From the low-energy tomosynthesis scan, a specific slice within the predetermined volume segment is reconstructed, while from the high-energy tomosynthesis scan a three-dimensional model of the predetermined volume segment is created, which also contains information about the contrast agent content per time per voxel. From this three-dimensional model, at different times, slice images of the particular slice are reconstructed, which then each contain information about the contrast agent content corresponding to the time. In other words, first a reconstruction and then a subtraction of the (in particular registered and motion-corrected) layers are performed.

The method according to the invention thus combines the temporary dual-energy subtraction of tomosynthesis results with the non-temporary dual-energy subtraction of two-dimensional images. In this case, a subtraction of first and second image data is understood by a dual-energy subtraction, the first image data being created with a higher x-ray radiation energy than the second image data. For this reason, the method is also called the two-spectrum method, since the X-ray radiation for generating the low-energy image data and the X-ray for generating the high-energy image data have different wavelengths. In other words, the dual energy subtraction refers to the subtraction of a low energy image from only one high energy image, both taken in a short time interval.

While the first and second image data are created in the non-temporary dual energy subtraction within a fairly short period of time (1-50 sec), the first and second image data are created at the temporary dual energy subtraction at different times, which can be several minutes apart. In the case of temporary dual-energy subtraction, multiple subtractions are performed by means of temporally spaced (or reconstructed) high-energy slice images, resulting in a sequence of subtraction images with which the course of the contrast agent can be represented.

In other words, the present invention combines Contrast Enhanced Dual Energy Tomosynthesis (CEDET) with Contrast Enhanced Digital Mammography (CEDM).

According to the invention, a distinction is made between the production of two-dimensional images (mammography) and tomosynthesis. By (digital) tomosynthesis is meant a combination of digital image capture and image processing with little movement of the x-ray tube or x-ray source. Tomosynthesis has some similarities to computed tomography (CT), but is considered a separate technique. While in computer tomography images during a full 360 ° rotation of the X-ray source are created around the subject to be examined, the x-ray source in the tomosynthesis pivots only by a small angle of, for example, 40 °, with only a small number of shots (typically between 7 and 60) are created. Through the use of high-resolution detectors a very high resolution in planes perpendicular to the so-called Z-axis (axis in the direction of the tomosynthesis angle 0 ° or vertical direction or orientation CC) can be achieved, even if the resolution in the direction of the Z- Axis is lower. The main field of application of tomosynthesis is the imaging of the female breast as a supplement or replacement of mammography. Compared to mammography, tomosynthesis works with a lower beam energy per projection. For example, given the same energy of the individual X-ray photons, the total beam energy (ie, the sum of the beam energies needed to produce all the projections of tomosynthesis) of tomosynthesis equals one to two times the beam energy to produce a two-dimensional image.

In order to determine the x-ray energy to produce the two-dimensional low-energy image, the at least one high-energy two-dimensional energy image and the high-energy tomosynthesis scan, corresponding information from earlier two-dimensional images and / or from earlier tomosynthesis scans may be used.

For example, the two-dimensional low energy image and the two-dimensional high energy image (s) may be created in the enhancement phase of the contrast agent to detect the rising edge of the contrast agent concentration. The high-energy tomosynthesis scan then represents, in particular, the washout phase (falling edge of the contrast agent concentration). Since the enhancement phase is generally shorter than the washout phase, the two-dimensional images (the low energy image and the at least one high energy image) become the concentration of the contrast agent or better used for the course of the contrast agent concentration, since few two-dimensional images can be created in a shorter time than is necessary to perform a tomosynthesis scan.

For example, a time interval can be specified in which an accumulation of the contrast agent within the predetermined volume section is likely to take place. The two-dimensional low energy image and the at least one two-dimensional high energy image are then automatically generated in this time interval.

As a result, it is ensured according to the invention that the two-dimensional low-energy image and the at least one two-dimensional high energy image are created in the enrichment phase of the contrast agent, so that the non-temporary dual-energy subtraction makes statements about the contrast agent course in this enrichment phase.

Prior to the subtraction of the two-dimensional low energy image from the at least one two-dimensional high energy image, registration of the two-dimensional low energy image and the at least one high-energy two-dimensional image advantageously takes place using an earlier two-dimensional low energy image of the predetermined volume segment created prior to administration of the contrast agent. This earlier two-dimensional low energy image is usually an image that was created in an earlier examination of the patient.

By registering, the images to be subtracted are adapted to each other in the best possible way and any movements of the object are corrected. The goal of image registration is to find a transformation that best matches the high energy image with the low energy image. This prevents that in the subtraction not matching image areas are subtracted from each other.

By using an earlier two-dimensional low-energy image during registration, when creating the currently generated two-dimensional images, it is advantageously possible to compensate for motion artifacts, positioning-related and compression-related object changes.

According to the invention, it is possible for the two-dimensional low-energy image and / or the at least one high-energy image to be created during the performance of the high-energy tomosynthesis scan. For this purpose, corresponding recording parameter settings (eg filter settings, tube voltage, tube current, recording duration) of the tomosynthesis device and corresponding energy supply parameters for an x-ray source of the tomosynthesis device are made when changing tomosynthesis recordings to record the two-dimensional low energy image and / or the at least one high energy image. To continue the tomosynthesis scan, these altered filter settings and changed energy delivery parameters must be changed back to their settings for tomosynthesis.

The creation of two-dimensional images during tomosynthesis allows Advantageously, that the two-dimensional images at any time (not necessarily before the tomosynthesis) can be created.

• 1. Erstellen des zweidimensionalen Niedrigenergiebildes des vorbestimmten Volumenabschnitts.
• 2. Erstellen des mindestens einen Hochenergiebildes des vorbestimmten Volumenabschnitts.
• 3. Erstellen eines weiteren zweidimensionalen Niedrigenergiebildes eines weiteren Volumenabschnitts eines weiteren Untersuchungsobjekts.
• 4. Erstellen mindestens eines weiteren Hochenergiebildes des weiteren Volumenabschnitts.
• 5. Durchführen eines weiteren Hochenergie-Tomosynthese-Scans des weiteren Volumenabschnitts.
• 6. Durchführen des Hochenergie-Tomosynthese-Scans des vorbestimmten Volumenabschnitts.

According to one embodiment of the invention, the following steps may be performed in the following order:

• 1. Create the two-dimensional low energy image of the predetermined volume section.
• 2. Create the at least one high energy image of the predetermined volume section.
• 3. Create another two-dimensional low-energy image of another volume section of another examination object.
• 4. Create at least one further high-energy image of the further volume section.
• 5. Perform another high-energy tomosynthesis scan of the further volume segment.
• 6. Perform the high energy tomosynthesis scan of the predetermined volume section.

In this case, the further two-dimensional low-energy image is subtracted from or in each case from the several further high-energy images in order to make visible the concentration of the contrast agent in the further volume section by means of this further non-temporary dual-energy subtraction on the basis of the results or result images produced thereby.

Image data of a previous low-energy tomosynthesis scan of the further volume section can be subtracted from image data of the high-energy tomosynthesis scan of the further volume section in the context of a temporary dual-energy subtraction in order to obtain corresponding results on the contrast agent course in the further volume section.

This embodiment according to the invention advantageously enables the examination of two different examination objects (for example, a right and a left breast of a patient) with only a single administration of the contrast agent.

The temporary dual-energy subtraction, in which image data of the earlier low-energy tomosynthesis scan is subtracted from image data of the high-energy tomosynthesis scan, is preceded in particular by a registration in which the image data of the earlier low-energy tomosynthesis scan with the image data of the High-energy tomosynthesis scans are registered depending on the two-dimensional low-energy image.

By using the two-dimensional low energy image at registration, when creating the high-energy tomosynthesis scan, motion artifacts, positioning-related, and compression-related object changes can be advantageously compensated.

In addition, it is possible that a time interval is specified in which a leaching of the contrast agent within the predetermined volume section is expected. Thereafter, the high-energy tomosynthesis is automatically performed in this time interval by adjusting high-energy tomosynthesis parameters (eg, the number of projections to be made or the interval between the projections) so as to make the high-energy tomosynthesis feasible in the given time interval is.

• 1. Erstellen des zweidimensionalen Niedrigenergiebildes des vorbestimmten Volumenabschnitts.
• 2. Erstellen eines weiteren zweidimensionalen Niedrigenergiebildes eines weiteren Volumenabschnitts.
• 3. Durchführen eines weiteren Hochenergie-Tomosynthese-Scans des weiteren Volumenabschnitts, wobei dabei auch ein oder mehrere weitere zweidimensionale Hochenergiebilder des weiteren Volumenabschnitts erstellt werden.
• 4. Durchführen des Hochenergie-Tomosynthese-Scans des vorbestimmten Volumenabschnitts, wobei dabei auch das eine oder die mehreren Hochenergiebilder des vorbestimmten Volumenabschnitts erstellt werden.

According to a further embodiment of the invention, the following steps can be carried out after the administration of the contrast agent in the following order:

• 1. Create the two-dimensional low energy image of the predetermined volume section.
• 2. Create another two-dimensional low-energy image of another volume section.
• 3. Carrying out a further high-energy tomosynthesis scan of the further volume section, whereby one or more further two-dimensional high-energy images of the further volume section are thereby also created.
• 4. Performing the high energy tomosynthesis scan of the predetermined volume section, thereby also creating the one or more high energy images of the predetermined volume section.

In this case, the further two-dimensional low-energy image is subtracted from the or each of the other high-energy images (non-temporary dual-energy subtraction). A temporary dual-energy subtraction of image data of a previous low-energy tomosynthesis scan, which was carried out before the administration of the contrast agent with respect to the further volume segment, of image data of the further high-energy tomosynthesis scan of the further volume segment can also be carried out.

• • Eine Kombination einer Dual-Energie-Bildgebung (Differenz aus dem zweidimensionale Niedrigenergiebild und den zweidimensionalen Hochenergiebildern) mit einer Darstellung der zeitlichen Anreicherung des Kontrastmittels und der Auswaschphase (insbesondere durch Ergebnisse der Hochenergie-Tomosynthese) ist möglich.
• • Durch die Erstellung von zweidimensionalen Bildern in der zeitlich kurzen Anreicherungsphase kann der Kontrastmittelsverlauf sehr genau bestimmt werden.
• • Durch den Einsatz der Hochenergie-Tomosynthese während der im Vergleich zur Anreicherungsphase zeitlich längeren Auswaschphase ist eine Lokalisierung beispielsweise von Läsionen und Tumoren auch im dreidimensionalen Raum möglich.

The method according to the invention offers the following advantages:

• • A combination of dual-energy imaging (difference between the two-dimensional low-energy image and the two-dimensional high energy images) with a representation of the temporal accumulation of the contrast agent and the washout phase (in particular by results of high-energy tomosynthesis) is possible.
• • By creating two-dimensional images in the short-term enrichment phase the contrast agent course can be determined very accurately.
• • By using high-energy tomosynthesis during the longer wash-out phase compared to the enrichment phase, localization of, for example, lesions and tumors is also possible in three-dimensional space.

• • Vorgeben eines Zeitintervalls, in welchem eine Anreicherung oder eine Auswaschung des Kontrastmittels innerhalb des vorbestimmten Volumenabschnitts erwartet wird.
• • Automatisches Durchführen eines Tomosynthese-Scans des vorbestimmten Volumenabschnitts in dem vorgegebenen Zeitinterval. Abhängig von den Ergebnissen dieses Tomosynthese-Scans wird die Konzentration des Kontrastmittels in dem vorbestimmten Volumenabschnitt dargestellt oder bestimmt.

In the context of the present invention, a further method for displaying a concentration of a contrast agent in a predetermined volume section of an examination subject by means of a tomosynthesis apparatus is also provided. This further method comprises the following steps:

• • Specifying a time interval in which an enrichment or a leaching of the contrast agent within the predetermined volume section is expected.
• • automatically performing a tomosynthesis scan of the predetermined volume section in the predetermined time interval. Depending on the results of this tomosynthesis scan, the concentration of the contrast agent in the predetermined volume section is displayed or determined.

By adjusting the tomosynthesis scan to the predefined time interval or synchronizing it with it, both the contrast agent course in the enrichment phase and the contrast agent course in the washout phase can be optimally displayed and measured by means of the tomosynthesis scan. Because of the high attenuation coefficient of the contrast agent, image contrast of any malignant tumor is sufficient, even with the low beam energy used to produce the projections during tomosynthesis (compared to mammography or two-dimensional imaging), to quantitatively (ie, by corresponding Pixel values). Since the projections made during the tomosynthesis are obtained sequentially in time, the tomosynthesis scan can be used to display and measure the contrast medium profile.

For example, a number of recordings to be made can be specified during a tomosynthesis scan. The time interval between two temporally successive recordings of these recordings to be made can then be adapted to the predetermined time interval in such a way that the predetermined number of recordings to be created is generated within the predetermined time interval.

This ensures that the predetermined number of recordings to be made is generated completely during the enrichment phase or during the washout phase. In other words, the tomosynthesis scan can thereby advantageously be synchronized with the administration of the contrast agent, so that the tomosynthesis scan takes place precisely in the time interval of interest (that is to say over the entire enrichment phase or over the entire washout phase). In other words, the scan speed is related to the dynamics of the contrast agent, i. H. adapted to the contrast medium course. Accordingly, the invention takes into account that the accumulation of the contrast agent is relatively fast (within about 10-50 s), so that a faster (short distance between successive shots) Tomosynthesis scan must be driven. In contrast, the time duration of the time course of interest in the precipitation of the contrast agent (washout phase) is a few minutes. Ie. the duration of the tomosynthesis scan is set so that this time period corresponds to the duration of the enrichment phase or washout phase.

According to the invention, it is possible that both the enrichment phase and the washout phase are followed with a tomosynthesis scan. For this purpose, a first time interval, in which the accumulation of the contrast agent within the predetermined volume section is expected, and a second time interval, in which the leaching of the contrast agent within the predetermined volume section is expected, can be predetermined. A first tomosynthesis scan is then performed in the first time interval and a second tomosynthesis scan in the second time interval to depict or determine the concentration of the contrast agent in the predetermined volume portion, depending on the results of these two tomosynthesis scans. Ie. the duration of the first tomosynthesis scan is set to correspond to the first time interval, and the duration of the second tomosynthesis scan is set to correspond to the second time interval.

Based on results of the tomosynthesis scan (s), slice images of the predetermined volume portion may be reconstructed in consideration of a kinetic model of a flow of the contrast agent within the predetermined volume fraction. The kinetic model is based on a system of equations with differential terms for determining the propagation of the contrast agent in the enrichment phase and / or the washout phase. The kinetic model is known from CE-MRI (Contrast Enhanced Magnetic Resonance Imaging), see "Imaging Systems for Medical Diagnostics"; A. Oppelt ISBN: 3-89578-226-2, pages 660-667 and "Automatic identification and classification of characteristic kinetic curves of breast lesions to DCE-MRI; W. Chen et al. Medical Physics, Vol. 8, August 2006; Pages 2878-2887 , The kinetic model is known from pharmacokinetics and describes the concentration of the contrast agent as a function of time with ordinary differential equations with parameters describing the uptake or release of the contrast medium (drug) into a compartment (vessel, cell, intracellular space). The pharmacokinetics researches and describes as a scientific branch of pharmacology mainly the effect of the body on an applied drug or in other words its temporal course in individual body regions.

By using the kinetic model in the reconstruction, changes due to different contrast agent concentrations at different times in the same volume portion can advantageously be taken into account in reconstructing three-dimensional image information of the predetermined volume portion from the projections made during tomosynthesis.

Moreover, it is possible to reconstruct image data using an iterative reconstruction algorithm based on the results of the tomosynthesis scan (s). In this case, the iterative reconstruction algorithm can contain a model of the contrast agent flow as a boundary condition for the projection images to be created. In other words, when creating the three-dimensional image information, the iterative reconstruction algorithm considers that different contrast agent concentrations (as a result of the contrast agent flow) prevail at different times in the same volume segment. As an iterative reconstruction algorithm, for example ART ("Algebraic Reconstruction Technique"), SART ("Simultaneous ART"), SIRT ("Simultaneous Iterative Reconstruction Technique"), ML ("Maximum Likelihood") or MAP ("Maximum Activity Projection") can be used ,

In the event that only a few tomosynthesis scans are performed (for example only two, namely a scan during the enrichment and a scan during the enrichment), the total dose or total energy of the X-rays during the tomosynthesis scans according to the invention can be reduced by a predetermined factor ( 2) higher than is normally the case with normal tomosynthesis.

By increasing the total dose of X-rays according to the predetermined factor, the quality of the image data produced and thus the reliability of the quantitative image evaluation can be increased.

In addition, the contrast agent concentration in the predetermined volume section can be determined from difference images. For this purpose, an image which was created prior to administration of the contrast agent from the predetermined volume section by means of a tomosynthesis device is subtracted from a further image, which is reconstructed on the basis of results of the tomosynthesis carried out according to the invention by the corresponding difference image, the concentration of the contrast agent in the predetermined Volume section to determine.

• • Im Vergleich zur Magnetresonanztomographie kann gerade in der schnellen Anreicherungsphase eine höhere Ortsauflösung und eine höhere Zeitauflösung realisiert werden.
• • Indem die Scan-Geschwindigkeit (d. h. die Zeitdauer, in welcher der Tomosynthese-Scan durchgeführt wird) an die Kontrastmittelsdynamik angepasst wird, kann die Gesamtstrahlendosis, mit welcher die Patientin belastet wird, optimal gering gehalten werden.

The further method according to the invention offers the following advantages:

• • In comparison to magnetic resonance tomography, a higher spatial resolution and a higher time resolution can be achieved, especially in the fast enrichment phase.
• By optimizing the scan speed (ie, the length of time the tomosynthesis scan is performed) to contrast agent dynamics, the total dose of radiation to which the patient is subjected can be optimally minimized.

It should be noted that the method according to the invention and the further method according to the invention can be combined with one another. In particular, the further method according to the invention for carrying out the high-energy tomosynthesis scan in the washout phase can be used.

The present invention also provides a tomosynthesis apparatus comprising a detector and an x-ray source for imitating x-rays directed to the detector. In this case, between the X-ray source and the detector, an examination object (in particular a female breast) can be positioned such that the X-rays pass through a predetermined volume section of the examination subject before they strike the detector. The tomosynthesis apparatus includes a controller for driving the X-ray source and the detector, and an image calculating unit for receiving data of the predetermined volume portion detected by the detector and forming an image representing a concentration of a contrast agent in the predetermined volume portion. The tomosynthesis apparatus, upon administration of a contrast agent, generates a two-dimensional low energy image of the predetermined volume portion and at least one two-dimensional high energy image of the predetermined volume segment, wherein a beam energy for producing a high energy image is substantially higher than the beam energy for creating the low energy image. In addition, the tomosynthesis device performs one after administration of the contrast agent High-energy tomosynthesis of the predetermined volume section, wherein a total radiation dose of high-energy tomosynthesis is much higher than a radiation dose for creating the two-dimensional low energy image. The controller uses the image calculation unit to subtract the two-dimensional low energy image from each high energy image (non-temporary dual energy subtraction) to produce a result image on which the concentration of the contrast agent can be represented.

The advantages of the tomosynthesis apparatus according to the invention essentially correspond to the advantages of the corresponding method according to the invention, which are carried out in advance in detail, so that a repetition is dispensed with here.

In the context of the present invention, another tomosynthesis apparatus is provided with a detector and an X-ray source for emitting X-rays directed to the detector. In this further tomosynthesis apparatus, an examination object (in particular a female breast) can be positioned between the x-ray source and the detector in such a way that the x-rays pass through a predetermined volume section of the examination subject before they strike the detector. The further tomosynthesis apparatus also comprises a controller for controlling the X-ray source and the detector and an image-calculating unit for receiving data of the predetermined volume section acquired by the detector and for producing an image from which a concentration of a contrast agent in the predetermined volume section can be derived. The controller is a time interval can be predetermined, in which an enrichment or a leaching of the contrast agent within the predetermined volume section is expected. Within the given time interval, the tomosynthesis device performs a tomosynthesis in order to determine the concentration of the contrast agent in the predetermined volume section, depending on the results of this tomosynthesis (the result is in particular an image).

The advantages of the further inventive Tomosynthesegeräts essentially correspond to the advantages of the further inventive method, which are carried out in advance in detail, so that is omitted here a repetition.

Furthermore, the present invention describes a computer program product, in particular a computer program or software, which can be loaded into a memory of a programmable controller or a computing unit of a tomosynthesis device. With this computer program product, all or various embodiments of the inventive methods described above can be carried out when the computer program product is running in the control or control device of the tomosynthesis device. The computer program product may require program resources, eg. As libraries and auxiliary functions to realize the corresponding embodiments of the method. In other words, with the claim directed to the computer program product, in particular a computer program or a software is to be protected, with which one of the above-described embodiments of the method according to the invention can be executed or which executes this embodiment. The software may be a source code (eg C ++) which still compiles (translates) and bound or which only needs to be interpreted, or an executable software code which only has to be executed in the corresponding arithmetic unit load is.

Finally, the present invention discloses an electronically readable medium, for. As a DVD, a magnetic tape or a USB stick on which electronically readable control information, in particular software (see above), is stored. When this control information (software) is read from the data medium and stored in a control unit of a tomosynthesis apparatus, all embodiments according to the invention of the methods described above can be carried out.

The present invention is particularly suitable for supplementing or expanding contrast-enhanced mammography. Of course, the present invention is not limited to this preferred field of application, since with the present invention, contrast agent courses or contrast agent concentrations can also be displayed in other body areas of a living organism.

In the following, the present invention will be described in detail based on preferred embodiments of the invention with reference to the figures.

1 schematically represents an inventive Tomosynthesegerät.

In 2 an inventive sequence of a dual-energy image acquisition, processing and presentation is shown beginning with the contrast agent.

In 3 is another inventive flow of a dual-energy image acquisition, processing and presentation starting with the Contrast agent presented, with two different volume sections are examined.

In 4 is another inventive flow of a dual-energy image acquisition, processing and presentation shown starting with the contrast agent, wherein two different volume sections are examined.

In 5 an inventive sequence for creating two-dimensional images during a high-energy tomosynthesis scan is shown.

In 6a and 6b a flow chart of a method according to the invention is shown.

In 1 schematically is a tomosynthesis device according to the invention 30 presented for mammography examinations. The tomosynthesis device 30 includes a support arm 9 , which is mounted in a bearing about a horizontal axis A pivotally (see double arrow or angle α). The storage is on a tripod 3 arranged and as indicated by the double arrow b vertically adjustable. On the support arm 9 are one with an x-ray source 5 provided arm 6 , an area detector 7 and one from a compression plate 10 and a bearing plate 11 existing compression device arranged. In the 1 is one of the compression plate 10 and the bearing plate 11 compressed female breast 12 shown in a schematic way. The arm 6 is relative to the support arm 1 , the detector 7 and the compression device 10 . 11 pivotable about the axis A. For height adjustments and swivel movements are electric motors 13 to 15 of the tomosynthesis device 30 intended.

A control of the Tomosynthesegeräts 30 via an operating device 16 of the tomosynthesis device 30 which with a control 17 and a image processing unit 22 of the tomosynthesis device 30 connected is. By means of a DVD 21 may use certain methods (including the method according to the invention) in the control 17 and the operating device 16 getting charged.

In 2 is a inventive principle of a dual-energy image acquisition, processing and display shown starting with the contrast agent. After administration of the contrast agent, the recording of a two-dimensional low-energy image takes place 1 the female breast (the predetermined volume section) usually in the form of a standard screening projection (CC or MLO). Subsequently, several two-dimensional high energy images 2 created with the same intake angle (CC or MLO) of the female breast. Using previous low energy images 31 the same breast of the patient is a registration of the low energy image 1 each with one of the high energy images 2 , After this registration 8th becomes the low energy image 1 from each of the high energy images 2 subtracted, resulting in each case a dual-energy image (difference image). This subtraction is also referred to as non-temporary dual energy subtraction. The concentration of the contrast agent is visible on each of these difference images, so that the contrast agent profile results from the several difference images.

The capture of two-dimensional low-energy image 1 and the recording of the two-dimensional high energy images 2 occurs in the enrichment phase of the contrast agent, since the creation of two-dimensional images 1 . 2 can be done quickly enough to these two-dimensional images 1 . 2 even with a short time enrichment phase of only 10 s to create.

After creating the two-dimensional high-energy images 2 (about 2 to 4 minutes after the administration of the contrast agent) is a high-energy tomosynthesis 4 performed on the same breast. Derived from high-energy tomosynthesis 4 resulting image data are using the two-dimensional low energy image 1 with image data from a previous low-energy tomosynthesis performed on the same breast 18 registered.

After registration 38 become the image data of high-energy tomosynthesis created from different tomosynthesis angles 4 adapted to each other so that a three-dimensional image data set of the female breast is created. Subsequently, a subtraction takes place 39 instead, in which the image data of the earlier low-energy tomosynthesis 18 from the image data of high-energy tomosynthesis 4 which is also known as a temporary dual-energy subtraction.

The high-energy tomosynthesis 4 This takes place in the washout phase, in which the contrast agent flows out of the lesions or tumors, so that the concentration of the contrast agent is reduced. This washout phase generally has a lower (negative) slope of the contrast agent concentration per unit time compared to the (positive) slope of the contrast agent concentration in the enhancement phase, so that more time is available to perform the high-energy tomosynthesis.

In 3 is a further inventive flow of a dual-energy image acquisition, processing and presentation shown starting with the contrast agent, wherein two different volume sections (both breasts) are examined.

After administering the contrast agent, first, the patient's right breast becomes a two-dimensional, low-energy image and then several high-energy, two-dimensional images 2 created. Subsequently, the right breast is released and from the left breast a two-dimensional low energy image 1' and subsequently several two-dimensional high energy images 2 ' created. After creating the two-dimensional high-energy images 2 ' becomes a high-energy tomosynthesis scan 4 ' the left breast performed. Subsequently, the left breast is released and a high-energy tomosynthesis scan 4 performed on the right breast.

With the in 3 Accordingly, both breasts of a patient can be examined with the same administration of a contrast agent. Because both the right and the left breast a low energy image 1 . 1' , several high energy pictures 2 . 2 ' and a high-energy tomosynthesis scan 4 . 4 ' can create a non-temporary dual-energy subtraction for both the right and the left breast 9 and a temporary dual-energy subtraction 39 be done as it is in 2 shown in detail for a breast.

In 4 is a variant of in 3 illustrated inventive sequence for examining both breasts. Compared to the in 3 shown process is missing in the 4 illustrated process the creation of two-dimensional high-energy images 2 . 2 ' the right and the left breast, thereby creating the two-dimensional images 1 . 1' faster and faster the high-energy tomosynthesis scan 4 . 4 ' can be started. The two-dimensional high energy images 2 ' The left breast will be during the high energy tomosynthesis scan 4 ' the left breast created during the two-dimensional high energy images 2 right breast during high energy tomosynthesis scan 4 the right breast are created.

In 5 is a variant of in 2 illustrated embodiment illustrated. At the in 5 The embodiment starts the high-energy tomosynthesis scan 4 immediately after administration of the contrast agent. During this high-energy tomosynthesis scan 4 become the two-dimensional low energy image 1 and the multiple two-dimensional high energy images 2 created.

In 6a a flow chart of an embodiment of the method according to the invention is shown.

In the first step S1, the patient is administered a contrast agent before the breast to be examined is positioned in the second step S2 between the bearing plate and the compression plate. These two first steps S1 and S2 can also be reversed in their order, so that the contrast agent is administered only when the breast to be examined is already positioned between the bearing plate and the compression plate.

Subsequently, in the following step S3, a two-dimensional low-energy image with a correspondingly low X-ray energy is generated as soon as possible after administration of the contrast agent. During the enrichment phase of the contrast agent in possibly present in the breast tumors and lesions several two-dimensional high-energy images are created with a correspondingly high X-ray energy in step S4.

Since the creation of two-dimensional images (mammography) is completed, the detector is switched from the two-dimensional mode to a tomosynthesis mode in step S5. Subsequently, in step S6, a high-energy tomosynthesis scan is performed with a correspondingly high beam energy in order to create image data of the washout phase of the contrast agent before the breast is released in step S7.

The processing of the images or image data created in steps S1 to S7 takes place in the in 6b illustrated steps. In this case, the steps S8 to S12 can also be performed in a different order than in 6b can be performed, provided that the registration of the corresponding images or image data takes place before a reconstruction or subtraction of these images or image data. Moreover, the steps S8 to S12 need not take place after the steps S1 to S7, but may be interleaved with these steps S1 to S7, provided that the images or image data required for a processing step S8 to S12 are prepared by the corresponding generation steps S3, S4, S6 are.

In step S8, the two-dimensional low energy image is formed 1 with each of the high energy images 2 registered, wherein this registration is performed depending on a two-dimensional low-energy image created before the administration of the contrast agent. Subsequently, in step S9, the low energy image is subtracted from each high energy image, whereby a number of dual energy images or reference images corresponding to the number of two-dimensional high energy images is created. The respective subtraction of the low energy image from the respective high energy image is also referred to as non-temporary dual energy subtraction.

In step S10, the image data of the high-energy tomosynthesis scan with image data registered a low-energy tomosynthesis scan performed before the administration of the contrast agent, this registration is performed depending on the two-dimensional low-energy image created in step S3. In step S11, three-dimensional image information of the examined breast is reconstructed from the projections produced in the high-energy tomosynthesis scan. Using this three-dimensional image information, it is possible to create arbitrary slice images (with arbitrary angles) of the examined breast. For representing the contrast agent concentration or the course of the contrast agent concentration in the washout phase, the image data of the earlier low-energy tomosynthesis scan are subtracted from the image data of the high-energy tomosynthesis scan, which is also known as a temporary dual-energy subtraction.

LIST OF REFERENCE NUMBERS

1, 1 '

Low-energy image

2, 2 '

High-energy image

3

tripod

4, 4 '

High-energy tomosynthesis

5

X-ray source

6

poor

7

detector

8th

Registration

9

subtraction

10, 11

compression plate

12

chest

13-15

electric motor

16

operating device

17

control

18

earlier low-energy tomosynthesis

19

reconstruction

21

DVD

22

calculator

30

Tomosynthesegerät

31

earlier low energy image

38

Registration

39

subtraction

A

axis

S1-S12

step

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• "Imaging Systems for Medical Diagnostics"; A. Oppelt ISBN: 3-89578-226-2, pages 660-667 [0037]
• "Automatic identification and classification of characteristic kinetic curves of breast lesions on DCE-MRI; W. Chen et al. Medical Physics, Vol. 8, August 2006; Pages 2878-2887 [0037]

Claims (23)

Method for representing a concentration of a contrast agent in a predetermined volume section of an examination object ( 12 ) by means of a tomosynthesis device ( 30 ), the method comprising the steps of: after administering the contrast agent, creating a two-dimensional low energy image ( 1 ) of the predetermined volume portion with a low beam energy, after the administration of the contrast agent, creating at least one two-dimensional high energy image ( 2 ) of the predetermined volume portion having a high beam energy, wherein the high beam energy is substantially higher than the low beam energy after the generation of the two-dimensional low energy image ( 1 ) Performing a high-energy tomosynthesis ( 4 ) of the predetermined volume portion having a high total beam energy, wherein the high total beam energy is substantially higher than the low beam energy, and subtracting the two-dimensional low energy image (FIG. 1 ) of the at least one two-dimensional high energy image ( 2 ) to produce a result with which the concentration of the contrast agent is visible. Method according to Claim 1, characterized in that the subtraction of the two-dimensional low-energy image ( 1 ) of the at least one high-energy two-dimensional image comprises a registration of the two-dimensional low-energy image and the at least one high-energy two-dimensional image, and that the registration depends on an earlier two-dimensional image ( 31 ) of the predetermined volume portion created before the administration of the contrast agent. Method according to claim 1 or 2, characterized in that a time interval is specified in which an accumulation of the contrast agent takes place within the predetermined volume section, and in that the two-dimensional low energy image ( 1 ) and the at least one two-dimensional high energy image ( 2 ) are automatically created in the time interval. Method according to one of the preceding claims, characterized in that the two-dimensional low-energy image ( 1 ) in the implementation of high-energy tomosynthesis ( 4 ) is created by setting corresponding acquisition parameter settings of the tomosynthesis device ( 30 ) and corresponding energy supply parameters for an X-ray source ( 5 ) of the Tomosynthesegeräts ( 30 ) when switching from high-energy tomosynthesis ( 4 ) to the creation of the two-dimensional low energy image ( 1 ) or vice versa. Method according to one of the preceding claims, characterized in that the at least one two-dimensional high energy image ( 2 ) in the implementation of high-energy tomosynthesis ( 4 ) is created by setting corresponding acquisition parameter settings of the tomosynthesis device ( 30 ) and corresponding energy supply parameters for an X-ray source ( 5 ) of the Tomosynthesegeräts ( 30 ) when switching from high-energy tomosynthesis ( 4 ) to the creation of the at least one two-dimensional high-energy image ( 2 ) or vice versa. Method according to one of the preceding claims, characterized in that for the same administration the following steps are carried out in the following order: a) Creation of the two-dimensional low-energy image ( 1 ) of the predetermined volume section, b) creating the at least one two-dimensional high-energy image ( 2 ) of the predetermined volume section, c) creating a further two-dimensional low-energy image ( 1' ) of a further predetermined volume section of a further examination subject with the low beam energy, d) creation of at least one further two-dimensional high-energy picture ( 2 ' ) of the further predetermined volume section with the high beam energy, e) carrying out a further high-energy tomosynthesis ( 4 ' ) of the further predetermined volume section with the high total beam energy, f) performing the high-energy tomosynthesis ( 4 ) of the predetermined volume section, and that also the further two-dimensional low energy image ( 1' ) of the at least one further two-dimensional high-energy image ( 2 ' ) is subtracted to produce a further result, with which the concentration of the contrast agent in the further predetermined volume section is visible. Method according to one of claims 1-5, characterized in that for the same administration the following steps are carried out in the following order: a) preparation of the two-dimensional low-energy image ( 1 ) of the predetermined volume section, b) creating a further two-dimensional low-energy image ( 1' ) of another predetermined volume portion of another low-energy research object, c) carrying out another high-energy tomosynthesis ( 4 ' ) of the further predetermined volume section with the high total beam energy, wherein during high-energy tomosynthesis ( 4 ' ) at least one further two-dimensional high-energy image ( 2 ' ) of the further predetermined volume section is created with the high beam energy, d) performing the high-energy tomosynthesis ( 4 ), during high-energy tomosynthesis ( 4 ) the at least one two-dimensional high-energy image ( 2 ) and that also the further two-dimensional low energy image ( 1' ) is subtracted from the at least one further two-dimensional high-energy image to produce a further result with which the concentration of the contrast agent in the further predetermined volume section is visible. Method according to one of the preceding claims, characterized in that a time interval is specified in which a leaching of the contrast agent within the predetermined volume section takes place, and that the high-energy tomosynthesis ( 4 ) is automatically performed in this time interval. Method according to one of the preceding claims, characterized in that a temporary dual-energy subtraction between image data of high-energy tomosynthesis and image data of a previous low-energy tomosynthesis, which is created prior to the administration of the contrast agent with a low total beam energy is performed. A method according to claim 9, characterized in that before the temporary dual-energy subtraction, a registration of the image data of the high-energy tomosynthesis and the image data of the earlier low-energy tomosynthesis is performed. Method for representing a concentration of a contrast agent in a predetermined volume section of an examination object ( 12 ) by means of a tomosynthesis device ( 30 ), the method comprising the steps of: specifying a time interval in which accumulation or leaching of the contrast agent occurs within the predetermined volume portion, and automatically performing tomosynthesis of the predetermined volume portion in the time interval to determine the concentration of the contrast agent based on tomosynthesis results in the predetermined volume section. Method according to claim 11, characterized, that a number of recordings to be made are given during tomosynthesis, and that a temporal distance between two temporally successive recordings of tomosynthesis the time interval is adjusted such that within the time interval, the number of recordings is created. Method according to claim 11 or 12, characterized, that a first time interval is specified in which the accumulation of the contrast agent takes place within the predetermined volume section, that a second time interval is specified in which the washout of the contrast agent takes place within the predetermined volume section, in that a first tomosynthesis in the first time interval and a second tomosynthesis in the second time interval are carried out in order to determine the concentration of the contrast agent in the predetermined volume section, depending on the results of the first tomosynthesis and the second tomosynthesis. Method according to one of Claims 11-13, characterized in that, on the basis of results of the tomosynthesis, slice images of the predetermined volume segment are reconstructed taking into account a kinetic model of a flow of the contrast agent in the predetermined volume segment. Method according to one of claims 11-14, characterized, that, based on the results of tomosynthesis, image data are reconstructed using an iterative reconstruction algorithm, and in that the iterative reconstruction algorithm takes into account a model of a flow of the contrast agent in the predetermined volume section as a boundary condition for the reconstruction. A method according to any one of claims 11-15, characterized in that a total beam energy of X-rays during tomosynthesis is greater by a predetermined factor than a normal total beam energy of X-rays during normal tomosynthesis. Method according to one of claims 11-16, characterized in that an image, which was created before administration of the contrast agent from the predetermined volume portion by means of a Tomosynthesegeräts, is subtracted from another image, which is reconstructed on the basis of results of tomosynthesis in order to determine the concentration of the contrast agent in the predetermined volume section. Tomosynthesis device with a detector ( 7 ) and an X-ray source ( 5 ) for emission to the detector ( 7 ) directed X-rays, wherein between the X-ray source ( 5 ) and the detector ( 7 ) an examination object ( 12 ) is positionable such that the x-rays comprise a predetermined volume portion of the examination object ( 12 ) before moving onto the detector ( 7 ), whereby the tomosynthesis device ( 30 ) a controller ( 17 ) for controlling the X-ray source ( 5 ) and the detector ( 7 ) and an image processing unit ( 22 ) for receiving from the detector ( 7 ) and to produce a result which represents a concentration of a contrast agent in the predetermined volume segment, the tomosynthesis apparatus ( 30 ) is configured such that the tomosynthesis device ( 30 ) after administration of a contrast agent, a two-dimensional low energy image ( 1 ) of the predetermined volume section with a low beam energy that the tomosynthesis device ( 30 ) after the administration of the contrast agent at least one two-dimensional high-energy image ( 1 ) of the predetermined volume section with a high beam energy, wherein the high beam energy is substantially higher than the low beam energy that the tomosynthesis device ( 30 ) after the creation of the two-dimensional low energy image ( 1 ) a high-energy tomosynthesis ( 4 ) of the predetermined volume portion having a high total beam energy, wherein the high total beam energy is substantially higher than the low beam energy, and wherein the controller ( 17 ) using the image processing unit ( 22 ) the two-dimensional low energy image ( 1 ) of the at least one two-dimensional high energy image ( 2 ) is subtracted to produce a result with which the concentration of the contrast agent is visible. Tomosynthesis device according to claim 18, characterized in that the tomosynthesis device ( 30 ) is designed for carrying out the method according to one of claims 1-10. Tomosynthesis device with a detector ( 7 ) and an X-ray source ( 5 ) for emission to the detector ( 7 ) directed X-rays, wherein between the X-ray source ( 5 ) and the detector ( 7 ) an examination object ( 12 ) is positionable such that the x-rays comprise a predetermined volume portion of the examination object ( 12 ) before moving onto the detector ( 7 ), whereby the tomosynthesis device ( 30 ) a controller ( 17 ) for controlling the X-ray source ( 5 ) and the detector ( 7 ) and an image processing unit ( 22 ) for receiving from the detector ( 7 ) and to produce a result which represents a concentration of a contrast agent in the predetermined volume segment, the tomosynthesis apparatus ( 30 ) is configured such that the controller ( 17 ), a time interval can be predetermined in which an enrichment or a washing out of the contrast agent takes place within the predetermined volume section, and in that the tomosynthesis apparatus ( 30 ) performs a tomosynthesis in the time interval to determine the concentration of the contrast agent in the predetermined volume section, depending on the results of the tomosynthesis. Tomosynthesegerät according to claim 20, characterized in that the Tomosynthesegerät ( 30 ) is configured for carrying out the method according to any one of claims 11-17. Computer program product comprising a program and directly into a memory of a programmable controller ( 17 ) of a Tomosynthesegeräts ( 30 ) with program means to perform all the steps of the method according to any one of claims 1-17, when the program in the controller ( 17 ) of the Tomosynthesegeräts ( 30 ) is performed. Electronically readable data carrier with electronically readable control information stored thereon, which are designed in such a way that when using the data carrier ( 21 ) in a controller ( 17 ) of a Tomosynthesegeräts ( 30 ) perform the method according to any one of claims 1-17.

Images